Electrical switch



O t- 9, 1951 A. A. LUTSKY ETAL ELECTRICAL SWITCH Filed Jan. 10. 1950 INVENTORS F|G.4 FIGS ARTHUR A. LuTskY ALBERT A. WALKER FIG-ll FIGJO Patented Oct. 9, 1951 ELECTRICAL SWITCH Arthur A. Lutsky, Newark, and Albert A. Walker, Succasunna, N. J assignors to The Daven Company, Newark, N. J., a corporation of New Jersey Application January 10, 1950, Serial No. 137,711

16 Claims. 1

This invention relates to electrical switches such as are employed in electrical communications field, and an object of the present invention is to provide a thin, neat appearing practical switch employing a minimum number of parts and requiring a relatively small amount'of manual labor to assemble it and connect it in a circuit.

An object of thepresent invention is to provide an electrical switch of the type employed in transducers, such as attenuators, potentiometers, etc., in which the circuit-carrying leads are in the form of flat metal strips bonded to the insulating plate and may be formed either by electrochemical or electrolytical deposit of the metal on the insulating carrying plate or by the bonding of a sheet of metal to the insulating plate which is then etched to remove-the metal except in those areas where the leads are required, thereby eliminating much hand wiring and the consequent multiple wires usually employed in such switches.

Another object of the present invention is the provision of a simplified electrical switch as specified wherein the contact-making arm or switch arm and the ring contact also act as a detent gear and paw], thereby eliminating the employment of a separate detent gear and pawl such as normally employed in switches of this character.

A further object of the invention is to provide a simplified switch structure wherein the switch arm is carried by the dialing knobs of the switch, being connected thereto for rotation with the knob in a simple. novel manner, and wherein the knob is rotatably supported upon the insulating contact-carrying plate by a simple relationship of stub shaft, bearing sleeve and snap ring.

With these and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing an electricalswitch of a preferred form embodying the invention, and the features forming the invention will be specifically pointed out in the claims.

In the drawings:

Figure 1 is'a front elevation of the improved electrical switch.

Figure 2 is an edge elevation of the switch.

Figure 3 is a plan view of the back of the switch structure. I

Figure 4 is a section on the line 4-4 of Figure 3 of the drawings showing the switch in a circuit: breaking position.

Figure 5 is a cross section through the switch taken on the line 55 of Figure 3 and showing the switch in a circuit making position.

Figure 6 is a plan view of the circuit-making and breaking switch arm.

Figure 7 is an edge elevation of the switch arm.

Figure 8 is a perspective view showing the manner of attaching the switch arm to the dialing knob.

Figure 9 is a detailed view of the contact ring.

Figure 10 is a detailed section taken on the line I 0-I 0 of Figure 8.

Figure 11 is a detailed view of a slight modification of. the switch structure.

Referring more particularly to the drawings, the improved electrical switch includes the contact carrying plate I which is mde of any suitable insulating material of sufiicient rigidity to form a supporting plate. The contact carrying plate I has a plurality of spaced contacts 2 carried .thereby and arranged in the usual ring concentric of an axis point through the plate. The contacts 2 of posts 3 formed thereon are attached thereto which extend through the plate I and through the inner ends of the thin fiat electric current conducting leads or lines 4 carried by the back of the plate I. The electric current conducting leads 4 consist of thin flat metal strips on the back of the plate I and they extend outwardly to terminals 5 sp? ced around the plate I near its edges thus providing permanent rigid electric current conducting leads from each of the independent or spaced contacts 2 to a terminal point near the edge of the plate I to facilitate the connection of the contacts in an eectrical circuit and eliminate not only the mult tude of wires leading from the relatively small space encompassed by the posts 3, but also eliminating the manual labor required for connecting such wires (not shown) to the posts 3. Furthermore, the employment of the thin fiat metal leads 4 very materially reduces the thickness of the switch structure which, together with other features hereinafter described, permits the provision of a thin switch which will require much less space than analogous switches as they are now manufactured.

A ring contact 6 is attached to the outer face of the plate I concentric of the ring of spaced contacts 2 by suitable means such as the eyelet rivets 1 shown in Figure 3. An electric current conducting lead 8 which is also a thin flat metal strip upon the back of the plate I is conductively connected to the contact ring 6 by the eyelet rivet I. The lead 8 extends out to near the edge of the plate l' and i connected to a terminal 9 to which a wire (not shown) may be connected.

The ring contact 9 has a plurality of circumferentially spaced bosses l struck thereon which are substantially semi-spherical in shape.

The dialing knob i I of the switch structure has a stub shaft l2 formed thereon which extends through a bearing collar l3 carried by the plate I. A snap ring I l engages the stub shaft and holds the stub shaft l2 against axial movement relative to the bearing sleeve l3 and the contact carrying plate I. The stub shaft i2 is rotatably supported by the bearing [3 so as to permit rotation of the dialing knob H. The dialing knob H has an annular flange I5 formed thereon, the outer surface of which is knurled, as shown at Hi. If it is so desired, the annular flange l5 may project above or beyond one edge of the contact carrying plate l as shown in Figures 1 and 2 of the drawings so as to facilitate rotation of the dialing knob by engagement with its knurled flange l5.

A bar I! extends diametrically across the inner hollow portion of the dialing knob H and it has its outer ends thickened as shown at Hi. The thickened ends I8 have recesses I9 formed therein in which the cars 28 formed on the switch arm 2| engage for connecting the switch arm 2| to the dialing knob l l for rotation therewith. In Figures 6 and 8 of the drawings the switch arm ,2! is shown as comprising a ring of electrical current conducting metal which has the diametrically opposed projecting cars 20 formed thereon at right angles to the diametrically opposed projecting ears 22 and 23. The ear 23 has a contact strap 2 struck outwardly from its inner face and the ear 22 has a boss 25 which is substantially semi-spherical in shape struck inwardly from its inner surface. is struck inwardly from the inner face of the switch arm 2! inwardly towards the axis of the arm from the boss 25 and spaced so that while the boss 25 will ride over and enga e the bosses Ill on the contact ring 5 the boss 26 will enga e any one of the spaced contacts 2. is of such len th that it will engage bet een two of the bosses It on the contact ring 6. As clearly shown in Fig res 5 and 7 of the dra ings, the switch arm 2| is bowed so as to provide spring action thereto and in such manner that its concave side faces the contact carrying plate I. The bowed switch arm together with the strap or boss 24 and boss 25 serve a dual function during the operation of t e switch, they, riding over the bos es I0, provide a d tent action for the switch, holding it in adusted ositions and thus eliminate the need of a detent gear and pawl such as normally employed in switches of this general type. Also the strap or boss 24 and boss 25 provide means for breaking an electrical circuit through the switch. When the dialing knob H is adiusted, as shown in Figure 4 of the drawings, with the strap or boss 24 and the boss 25 engaging on a pair of diametrically opposed bosses H), the boss 26 is held out of engagement with any one of the contacts 2 and thus the electrical circuit is broken. When the dial it is adjusted so that the bowed strap or boss 24 engages between two adjacent bosses the spring action of the switch arm 2! cau es it to assume its bowed position as shown in Figure 5 thus moving the boss 26 into engagement with one of the contacts 2 and closing an electrical circuit through the switch structure.

As shown in Figures 2, 4 and 5 of the drawings,

A second boss 25 The strap 24 the provision of the novel type of switch arm carried by the dialing knob ll together with the novel type of ring contact not only eliminate the need of a detent gear and pawl in the switch structure but materially simplifies the construction of the switch and permits the construction of a switch which is very much thinner and consequently occupies much less space than corresponding or analogous switches of approved construction now in use. The bowing of the switch arm 2| provides sufiicient spring action to permit positive non-slipping adjusted movements of the switch arm and dialing knob and also provides quick snap make-and-break action of the switch.

The current carrying leads 4 and 8 may be formed on the insulating contact carrying plate I by various well known methods such as by electrochemical or electrolytical depositing of the metal on the insulating plate or by means of bonding a sheet of metal to the plate of insulation and then etched to remove all of the metal except in those areas where the leads are required.

As shown in Figure 11 of the drawings, the lug 22 or car and, consequently, the boss or extrusion 25 on the switch arm 2| may be eliminated which will permit use of the switch as a circuit shorting type switch.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they may be widely modified within the invention defined by the claims.

What is claimed is:

1. In an electrical switch, an insulation contact carrying plate, a plurality of spaced contacts carried by said contact carrying plate, a ring contact carried by said plate, a plurality of thin flat electrical current conducting leads on one side of said contact carrying plate and connected one to each of said spaced contacts, an electric current conducting lead on said contact carry ing plate and connected to said ring contact, a dialing knob rotatably carried by said contact carrying plate, a circuit-closing switch arm detachably connected. to said dialing knob for rotation therewith, and contact bosses formed on said ring contact, means formed on said switch arm cooperating with said bosses to provide detent action for the knob and switch arm.

2. In an electrical switch, an insulation contact carrying plate, a plurality of spaced contacts carried by said contact carrying plate, a ring contact carried by said plate, a plurality of thin flat electrical current conducting leads on one side of said contact carrying plate and connected one to each of said spaced contacts, an electric current conducting lead on said contact carrying plate and connected to said ring contact, a dialing knob rotatably carried by said contact carrying plate, and a circuit closing switch arm detach ably connected to said dialing knob for rotation therewith, said ring contact having a plurality of bosses formed thereon, and said switch arm having a pair of bosses formed thereon cooperating with said ring contact bosses to provide detent action.

3. In an electrical switch, an insulation contact carrying plate, a plurality of spaced contacts carried by said contact carrying plate, a ring contact carried by said plate, a plurality of thin flat electrical current conducting leads on one side of said contact carrying plate and connected one to each of said spaced contacts, an electric cur ent eei q l s lead 9!! said Contact yingplate and connected formed on saidswitch-arm and cooperating withsaid ringcontact bosses to provide detent action,

said switch arm having acontactboss thereon ion engagement with anyoneof said'spaced contacts; said switch arm being bowed to providespring action to hold the bosses thereon in contact -with;a ringcontact at all times and to hold the contact-boss on the switch arm out of contact with any of saidspaced contacts when the bosses on the switch arm are in engagement with bosses on the ring: contact.

4. An electrical switch as claimed in.claim,2 wherein said dialing knob hasapair of spaced recesses in its inner srrface, said switch arm having earsw thereon fitting in said recesses to connect the switch arm to thedialing knob for rotation therewith.

5: An electrical switch as claimed in claim 3 wherein said dialing knob has a stub shaft thereon, a bearing collar carried by said contact carr lng plate, said stub shaft extending rota-tably through said bearing collar, means for preventing longitudinal displacement of said shaft in said bearing collar, said dialing knob having a pair of spaced recesses in its inner surface, said switch arm having ears thereon fitting in said recesses to connect the switch arm to the dialing knob for rotation therewith.

6. In an electrical s itch, an insu ation contact carrying plate, a plurality of spaced contacts carried by said plate, a ring contact carried by said plate, said ring contact having a plurality of circumferentially spaced bosses thereon, a switch arm, means for rotatably supporting said switch arm, said switch arm provided with a pair of bosses spaced one on each side of the axis of rotation of the arm and adapted to coact with the bosses on the ring contact to provide detent action.

'7. An ele tri al switch. as claimed in. claim 6 including a contact boss formed on said switch arm for contact with any one of said plurality of contacts.

8. An electrical sw tch as cla med in c aim R including, a contact boss formed on said switch arm for contact with any one of said s aced contacts, sa d switch arm being bowed to provide spring action in the switch arm to mainta n said pair of bosses always in cont ct ith the in contact and to move the cont ct boss on he s it h arm out of enga ement with a spaced conta t when the pair of bosses on the switch arm are in engagement with bosses on the rin conta t.

9. In an electrical switch an insulation contact carr ing plate. a plurality of spaced contacts c rried by said plate, a rin contact carried by said plate. said ring contact h vin a pluralitv of circumferentiall s a ed bosses thereon. a dialing knob rotat blv carried b sa d conta t "arlV- ins. plate, a switch a m connected to said dia ing knob for rotation therewith, said switch arm provided with a pair of bosses s aced one on each side of the axis of rotat on of the switch arm and adapted to coact with the bosses on the ring contact to pro ide detent a tion.

10. An ele tri al switch as c aimed in laim 9 including, a cont ct boss formed on said swit h arm for contact with an one of sa d lural t of spaced contacts, said switch arm eing owed to provide spring action in the switch arm to mainto said ring contact, adialing knob rotatably' carried by i said contactcarryingplate, and a circuit closing switch arm-- tain said pair of bosses always in contact with the ring contact and to move the contact boss out of engagement with the spaced contacts when the pair of bosses on'the switch arm are in engagement with bosses on the ring contact.

11. An electrical switch as claimed-in claim 9 including, a contact boss formed on said switch arm for contact with any one of said plurality of spaced contacts, said switch arm icing bowed to provide spring action in the switch arm to maintain said pair of bosses always in contact with the ring contact and to move the-contactboss out of engagement with the spaced contacts when the pair of bosses on the switch arm are in engagementwith bosses on the. ring contact, said dialing knob having spaced recesses in its inner surface, ears'formed on said switch arm and engaging in said recesses to detachably connect the switch armto the dialing knob for rotation therewith.

12. In an electrical switch, an insulation contact carrying plate, a plurality of spaced conring contact carriedby said plate, a plurality of thin fiat electrical current conducting leads on one side of said contact carrying plate and connected one to each of said spaced contacts, an electric current conducting lead on said contact carrying plate and connected to said ring contact, a dialing knob rotatably carried by said contact carrying plate, and a circuit closing switch arm detachably connected to said dialing knob for rotation therewith, said ring contact having a plurality of bosses thereon, a pair of bosses formed on said switch arrn cooperating with the ring contact bosses to provide detent action. said dialing knob having a pair of spaced recesses in its inner surface, and ears formed on said switch arm and fittin in said recesses to detachably connect the swit h arm to the dialing knob for rotation therewith.

13. In an elect ical switch. an insulation contact carrying plate, a plural ty of s aced con ta ts car ied bv said contact carrying plate, a ring conta t carried by said plate, a plurality of thin f at electrical current conducting leads on one side of said contact carr ing plate and connected one to each of aid spaced contacts. an electric cur ent cond ctin le d on said contact carrying l te and conne ted to said ring contact. a dialin knob rotat hly car ied by said contact carr in ate, and a circuit closing switch arm det chably co nected to said dialing knob for rotat on. therewith. a plur lity of bosses ormed on said ring conta t. a p i of bosses f rmed on sa d s itch arm and o e atin with sa d r n ontact bo ses to provide detent action, said switch a m having a contact boss thereon for enga ement with an one of said spaced contacts. sa d switch a m being towed to provide sprin acti n t h ld the bosses hereon in content with the rin contact at all times and to hold the contact boss on the sw tch arm out of contact with any of said spaced contacts when the bosses on the s itch arm are in en agement with bosses on the ring contact, said dialing knob having a pair of spaced recesses in its inner surface, said switch arm having ears thereon fitting in said recess to connect the switch arm to the dialing knob for rotation therewith, a stub shaft on said dialing knob. a bearing collar carried by sa d contact carrying late, said stub shaft rotatably mounted in said bearing collar, and means for preventing longitudinal displacement of said stub shaft relative to said bearing collar.

. 14. In an electrical switch, an insulation contact carrying plate, a plurality of spaced contacts carried by said contact carrying plate, a ring contact carried by said plate, a plurality of thin fiat electrical current conducting leads on one side of said contact carrying plate and connected one to each of said spaced contacts, an electric current conducting lead on said contact carrying plate and connected to said ring contact, a dialing knob rotatably carried by said contact carrying plate, and a circuit closing switch arm detachably connected to said dialing knob for rotation therewith, said dialing knob having a recess in its inner side, said ring contact and said spaced contacts extending into said recess and said circuit closing switch arm located wholly within the recess in said knob.

15. An electrical switch as claimed in claim 2 wherein said dialing knob has its inner portion cut away to form a recess in its inner side, said ring contact and said spaced contacts extending into said recess, and said circuit closing switch arm located wholly within the recess in said knob, said dialing knob having a pair of diametrically opposed recesses in inner wall of the recess there REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,127,808 Reynolds Feb. 9, 1915 2,354,750 Hall Aug. 1, 1944 2,411,013

Warnke Nov. 12, 1946 

